JP7237040B2 - Embossed film, sheet-fed film, transfer, and method for producing embossed film - Google Patents

Description

TECHNICAL FIELD The present invention relates to an embossed film, a sheet-fed film, a transfer, and a method for producing an embossed film.

In recent years, embossed films having various planar uneven structures have been developed and used.

As a method for producing such an embossed film, for example, there is a method of forming an uneven structure on a sheet-like transfer-receiving film using a stamper master.

Specifically, a stamper master disc is prepared by forming a reverse shape of the concave-convex structure to be formed on the film on the surface (transfer surface) of a flat substrate, and pressing the stamper master disc against the film to be transferred. The shape of the transfer surface is transferred to the transferred film. By repeating such transfer, it is possible to produce an embossed film in which a desired concavo-convex structure is formed over almost the entire area of the sheet-like transfer-receiving film.

JP 2009-258751 A

However, in the above-described method of producing an embossed film using a stamper master, it is difficult to accurately control the pressing position of the stamper master against the transferred film. Therefore, there is a problem that a positional deviation occurs between the arrangement pattern of the concave-convex structure formed by one transfer of the stamper master disk and the arrangement pattern of the concave-convex structure formed by the next transfer.

Further, in the stamper master disc, the more the transfer is repeated, the more likely it is that the convex portions of the stamper master disc will be worn away or the concave portions will be filled with the peeled film. Therefore, as the area of the embossed film to be produced increases, the transferability of the rugged structure to the film to be transferred decreases, and the frequency of defects in the embossed structure to be transferred increases.

Patent Document 1 discloses a method of producing a film or the like having a moth-eye structure with a period equal to or shorter than the wavelength of visible light by a roll-to-roll method using a cylindrical or cylindrical master. However, the technique disclosed in Patent Document 1 aims to form an uneven structure (for example, 1 μm or less) formed with a period equal to or less than the wavelength of visible light, so it does not contribute to solving the above problem. rice field.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved embossed film in which the frequency of defects in recesses in a transferred film is reduced, and the embossed film. An object of the present invention is to provide a cut sheet-fed film, a transfer product from the embossed film, and a method for producing the embossed film.

In order to solve the above problems, according to one aspect of the present invention, a film body and a plurality of recesses formed on the surface of the film body are provided, and the diameter of the opening surface of the recesses is a visible light wavelength The arrangement pattern of the recesses has a periodicity along the length direction of the film body, and the defect rate of the recesses at one end of the film body and the other end of the film body An embossed film having a difference of 10 ppm or less from the defect rate of recesses in the embossed film is provided.

The defect ratio of the recesses may be calculated based on the recesses in the region corresponding to the same arrangement pattern during one cycle of the arrangement pattern.

The film body may be a long film.

The recesses formed in the film body may have substantially the same shape.

The arrangement pattern of the recesses may be a lattice shape.

A number density of the concave portions may be 50000000/cm ² or less.

The film body may include a coating layer made of an inorganic compound on at least part of the surface including the inside of the recess.

The film body may be made of a curable resin or a plastic resin.

Moreover, in order to solve the above problems, according to another aspect of the present invention, there is provided a sheet-fed film formed by cutting the embossed film described above into a plurality of sheets.

Further, in order to solve the above problems, according to still another aspect of the present invention, the embossed film or sheet film described above is used, and micro solids are transferred to positions corresponding to the array pattern. A transcript is also provided.

Furthermore, in order to solve the above problems, according to still another aspect of the present invention, there is provided a step of forming a plurality of protrusions on the peripheral surface of a cylindrical or columnar master, and is rotated and pressed to transfer recesses corresponding to the peripheral surface shape of the master to the transferred film to produce a film body, wherein the diameter of the opening surface of the recesses is greater than the visible light wavelength. is large, and the difference between the defect rate of the recesses at one end of the film body and the defect rate of the recesses at the other end of the film body is 10 ppm or less. .

As described above, according to the present invention, when a concave portion having an opening surface with a diameter larger than the wavelength of visible light is formed in a film, the defect rate of the concave portion at one end of the film and the loss rate at the other end of the film It is possible to reduce the difference from the defect rate of the concave portion. Therefore, even when the embossed film is formed with a large area, it is possible to further reduce the frequency of defects in the concave portions.

1 is a cross-sectional view schematically showing a cross-sectional shape of an embossed film according to an embodiment of the present invention when cut in the thickness direction; FIG. It is a top view which shows an example of the arrangement pattern of the recessed part of the embossed film which concerns on the same embodiment. FIG. 3 is a schematic diagram showing an example of a cylindrical master for forming recesses of the embossed film shown in FIG. 2; It is an explanatory view for explaining one example of use of the embossed film concerning the embodiment. FIG. 4 is a cross-sectional view schematically showing a cross-sectional shape of a transfer product using the embossed film according to the same embodiment cut in the thickness direction. It is a top view which shows the planar state of the transcription|transfer material using the embossed film which concerns on the same embodiment. It is an explanatory view showing composition of exposure device which draws arbitrary patterns to a master disc used in the embodiment. It is an explanatory view showing typically a transcription device which produces an embossed film concerning the embodiment. It is an observation image by SEM of the embossed film according to the same embodiment. It is an observation image by SEM of the embossed film according to the same embodiment.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

<1. Embossed film>
[1.1. Structure of embossed film]
First, the structure of an embossed film according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a cross-sectional view schematically showing the cross-sectional shape of the embossed film 1 according to this embodiment when cut in the thickness direction.

As shown in FIG. 1 , the embossed film 1 according to this embodiment has a film body 10 and a plurality of convex portions 11 and concave portions 13 formed on the surface of the film body 10 .

Here, the laminated structure of the embossed film 1 is not limited to the structure shown in FIG. For example, the embossed film 1 may be formed as a laminate in which a plurality of resin layers are laminated. For example, the embossed film 1 may have a structure in which a support (not shown) made of resin or the like is laminated on the surface of the film body 10 opposite to the surface on which the projections 11 and the recesses 13 are formed. good. The support may be made of any resin, such as PET (polyethylene terephthalate) resin.

The film body 10 is made of a curable or plastic resin. Any known resin can be used for the film body 10 as long as it is a curable or plastic resin. Specifically, the film main body 10 may be formed of a photocurable resin or a thermosetting resin that is a curable resin, or a thermoplastic resin that is a plastic resin (more specifically, a crystal that melts due to heat). resin). The curable or plastic resin may be mixed with other film-forming materials.

When the film body 10 is formed of a thermoplastic resin, for example, after the film body 10 is heated and softened, a cylindrical or columnar master is pressed so that the concave-convex structure formed on the surface of the master is removed from the film body. 10 can be transferred. When the film main body 10 is formed of a photocurable resin, for example, the photocurable resin is applied to the support, and the photocurable resin is cured by irradiating light while pressing the cylindrical or cylindrical master. Thereby, the concave-convex structure formed on the surface of the master can be transferred to the film main body 10 .

The thickness of the film body 10 is not particularly limited, but may be, for example, 8 μm or more and 200 μm or less. Moreover, when the embossed film 1 is formed as a laminate of a support and a film body 10, the thickness of the entire embossed film 1 is not particularly limited, but may be, for example, 10 μm or more and 300 μm or less. In such a case, the thickness of the film body 10 alone may be 1 μm or more and 50 μm or less, and the thickness of the support alone may be 9 μm or more and 250 μm or less.

The protrusions 11 and the recesses 13 are uneven structures formed on the film body 10 . Here, the planar shape and cross-sectional shape of the convex portion 11 and the concave portion 13 are arbitrary, but the size of the planar shape of the convex portion 11 and the concave portion 13 is formed so as to be larger than the visible light wavelength.

Specifically, the concave portion 13 is formed so that the diameter of the opening surface is larger than the visible light wavelength. When the shape of the opening surface of the recess 13 is not circular (eg polygonal), the recess 13 is formed so that the diameter of the circumscribed circle of the shape of the opening surface is larger than the visible light wavelength. However, when the shape of the opening surface of the recess 13 is triangular or rectangular, the recess 13 may be formed so that the length of one side of the opening surface is longer than the visible light wavelength.

More specifically, the concave portion 13 may be formed so that the diameter of the opening surface is 0.8 μm or more and 500 μm or less, preferably 1.0 μm or more and 300 μm or less. Preferably, it may be formed to be larger than 1.6 μm and smaller than 300 μm. That is, the diameter of the opening surface of the concave portion 13 is preferably 0.8 μm or more, more preferably 1.0 μm or more, and even more preferably larger than 1.6 μm. Moreover, the diameter of the opening surface of the concave portion 13 is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably less than 300 μm.

The shape of the opening surface of the recess 13 may be any shape as described above. For example, the shape of the opening surface of the recess 13 may be circular, elliptical, rectangular, polygonal, or the like. Further, the shape of the opening surface of the concave portion 13 may be a shape including a curved line in part. The area of the opening surface of the concave portion 13 does not have to be constant as long as the diameter of the opening surface satisfies the above conditions.

Further, the depth of the concave portion 13 may be, for example, 0.08 μm or more and 30 μm or less, preferably 15 μm or less. Furthermore, when the shape of the opening surface of the recess 13 is approximately rectangular or approximately circular, the aspect ratio of the recess 13 may be 0.1 or more and 10 or less. Here, the aspect ratio of the recess 13 is defined as a ratio obtained by dividing the depth of the recess 13 by the minimum diameter or the minimum side length of the opening surface of the recess 13 .

If the depth of the recesses 13 exceeds 30 μm or the aspect ratio of the recesses 13 exceeds 10, the formation of the recesses 13 becomes difficult, which is not preferable. In addition, if the depth of the recesses 13 is less than 0.08 μm or the aspect ratio of the recesses 13 is less than 0.1, the effect of embossing the film body 10 is reduced, which is not preferable.

Here, when the embossed film 1 is formed only by the film body 10 , it is preferable that the depth of the recesses 13 does not exceed the thickness of the film body 10 . However, if the embossed film 1 is formed as a laminate of a support and a film body 10, the depth of the recesses 13 may exceed the thickness of the film body 10 (i.e., the recesses 13 may extend beyond the thickness of the film body 10). ).

Moreover, it is preferable that the cross-sectional shape of the concave portion 13 is substantially the same as long as the concave portion 13 has the same opening shape and depth over the entire film body 10 . As an example, it is preferable that the shape of the opening surface of the concave portion 13 is substantially the same over the entire film body 10 . When the cross-sectional shape or the shape of the opening surface of the recesses 13 is substantially the same, it is preferable because it becomes easier to grasp the formation state of the recesses 13 in the embossed film 1 .

A coating layer may be provided on at least part of the surface of the film body 10 on which the projections 11 and the recesses 13 are formed. Specifically, the coating layer may be provided on all of the upper surface of the projections 11 of the film body 10 and the sidewalls and bottom surface of the recesses 13, and the coating layer may be provided on part of the sidewalls and bottom surface of the recesses 13 of the film body 10. may be provided. However, the thickness of the coating layer may be substantially constant over the entire surface regardless of the shape of the recess 13 . The coating layer may be, for example, a layer made of an inorganic compound, or a layer made of an organic compound such as a surface modifier.

In addition, when the coating layer is a layer made of an organic compound, the material of the coating layer is preferably different from the material of the film main body 10 in which the concave portions 13 are formed. In such a case, the coating layer is preferably thick enough to be recognized as being deposited in a part of the recess 13. Specifically, the volume of the deposited coating layer is the entire space of the recess 13. It is preferably 30% by volume or less of the product.

By forming such a coating layer, the surface condition of the embossed film 1 can be further stabilized. Also, the coating layer may be formed so as to incline the wall surface of the recess 13 . In such a case, transfer of the filler filled in the concave portion 13 can be facilitated in a usage example described later.

Next, the arrangement pattern of the concave portions 13 of the embossed film 1 according to this embodiment will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a top view showing an example of the arrangement pattern of the concave portions 13 of the embossed film 1 according to this embodiment. FIG. 3 is a schematic diagram showing an example of a cylindrical master plate for forming the concave portions 13 of the embossed film 1 shown in FIG.

As shown in FIG. 2, the film body 10 is, for example, a long film. Specifically, the lower limit of the length of the film body 10 may be any of 5m, 10m, 30m, 50m, 100m, 200m, 300m, and 500m. The width of the film body 10 is not particularly limited, but is, for example, 0.05 cm or more and 300 cm or less.

Also, the arrangement pattern of the concave portions 13 formed in the film body 10 has periodicity along the length direction of the film body 10 . This is because, in the embossed film 1 according to the present embodiment, the projections 11 and the recesses 13 are formed by pressing the cylindrical or columnar master against the film body 10 in a roll-to-roll manner. Therefore, in the embossed film 1, the projections 11 and the recesses 13 are formed in an arrangement pattern having at least a periodicity corresponding to one circumference of a cylindrical or cylindrical master.

Specifically, FIG. 3 shows an example of a cylindrical master 4 for forming the concave portions 13 of the embossed film 1 shown in FIG. As shown in FIG. 3, on the outer peripheral surface of the cylindrical master 4, a concave-convex structure 41 corresponding to the convex portions 11 and concave portions 13 shown in FIG. 2 is formed. Here, the A direction of the uneven structure 41 formed on the outer peripheral surface of the cylindrical master 4 is the width direction of the embossed film 1 , and the B direction of the uneven structure 41 is the length direction of the embossed film 1 .

As illustrated in FIG. 3, the uneven structure 41 may be an arrangement pattern having periodicity such as a hexagonal lattice, or may be an arbitrary arrangement pattern having no periodicity. However, since the cylindrical master 4 presses the film main body 10 while rotating to transfer the uneven structure 41 to the film main body 10, the arrangement pattern of the convex portions 11 and the concave portions 13 formed on the embossed film 1 is a cylindrical shape. It necessarily has a periodicity corresponding to one round of the master disk 4 of the shape.

Also, the arrangement pattern of the concave portions 13 formed in the film body 10 may have periodicity along the direction orthogonal to the length direction of the film body 10 (that is, the width direction of the film body 10). That is, along the width direction of the film body 10, the concave portions 13 having the same shape may be repeatedly formed. Also, the arrangement pattern of the concave portions 13 may have the same repeating period in both the length direction and the width direction of the film body 10 . This is because when the formed embossed film 1 is cut to form a sheet-fed film, substantially the same film can be obtained both in the length direction and the width direction.

Here, in general, in the embossed film 1 produced by transferring from the pattern master, the defective part 15 may be generated due to transfer failure when the film body 10 is pressed from the pattern master. The missing portion 15 represents, for example, a portion in which the concave portion 13 is not formed at a position where the concave portion 13 should be formed in the array pattern to be transferred. Such a missing portion 15 is caused by abrasion of the convex structure or resin clogging of the concave structure due to continuous use of the pattern master. Therefore, the missing portions 15 tended to cumulatively increase as the uneven structure was transferred to the film body 10 having a larger area.

In the embossed film 1 according to this embodiment, the difference between the defect rate of the concave portions 13 at one end of the film body 10 and the defect rate of the concave portions 13 at the other end of the film body 10 is 10 ppm or less. Note that the defect rate represents the ratio of the defect portions 15 to all the recess portions 13 in a predetermined area. As a result, the embossed film 1 according to the present embodiment improves the uniformity of the concave-convex structure in the large-area film body 10 and reduces the frequency of occurrence of the defective portions 15 . The lower limit of the difference between the defect rate of the concave portions 13 at one end of the film body 10 and the defect rate of the concave portions 13 at the other end of the film body 10 is not particularly limited, but the smaller the better. , 0 are most preferred.

More specifically, when the recesses 13 are formed in the film body 10 in the direction of the arrow L, the loss rate of the recesses 13 in the region F, which is one end of the film body 10, and the other end of the film body 10 is 10 ppm or less. Here, since the arrangement pattern of the recesses 13 has periodicity along the length direction of the film body 10, the regions F and the regions R have the same arrangement pattern of the recesses 13 in one period of the arrangement pattern. A formed area is selected. That is, the defect rate of the concave portions 13 formed in the film body 10 is compared between regions having the same arrangement pattern of the concave portions 13 .

In addition, in the embossed film 1 according to the present embodiment, the missing portion 15 is generated continuously in the length direction of the film body 10 (more specifically, the direction in which the concave portion 13 is formed, that is, the direction of arrow L). is suppressed. Specifically, the embossed film 1 can have 10 or less, preferably 5 or less, continuous cutouts 15 in a range of 10 cm ² of the film body 10 . Here, the term "continuous missing portion 15" means that the adjacent concave portions 13 are not patterned and form the missing portion 15. As shown in FIG. Although the lower limit of the number of continuous missing portions 15 in the range of 10 cm ² of the film body 10 is not particularly limited, it is preferable that the number is as small as possible, and it goes without saying that 0 is the most preferable.

The arrangement pattern of the recesses 13 is not particularly limited, and may be any arrangement pattern. However, the number density of the concave portions 13 is preferably 50000000/cm ² or less. When the number density of the recesses 13 exceeds 50000000/cm ² , the contact area between the cylindrical or cylindrical master and the film body 10 increases when the recesses 13 are formed, and the releasability between the master and the film body 10 increases. is not preferable because it becomes difficult to form the concave portion 13. Although the lower limit of the number density of the recesses 13 is not particularly limited, it may be, for example, 100/cm ² or more.

Also, the interval between the recesses 13 (that is, the pitch of the recesses 13 in the array pattern) may be, for example, 0.5 μm or more and 1000 μm or less. In addition, the interval between the concave portions 13 refers to the distance between the centers of the opening surfaces of the adjacent concave portions 13 .

Here, various shapes can be mentioned as the shape and arrangement pattern of the opening surface of the recesses 13, and examples thereof include lattice shapes such as a square lattice, an orthorhombic lattice, a hexagonal lattice, and a parallel lattice. . Further, the shape of the opening surface of the recess 13 may be circular, rectangular, or curved. The arrangement pattern of the recesses 13 may be any arrangement pattern as long as it has periodicity, and may be, for example, a mixture of a plurality of arrangement patterns. When a plurality of arrangement patterns are mixed, the total number density of the recesses 13 in each arrangement pattern is preferably 50000000/cm ² or less.

Further, instead of the concave portions 13 described above, it is also possible to form the convex portions 11 having the shape and arrangement pattern of the concave portions 13 described above. That is, it is also possible to form the projections 11 having a reversed shape of the arrangement pattern of the recesses 13 described above. It is also possible to form In such a case, it is preferable to calculate the defect rate, which will be described later, using the presence or absence of defect of the convex portion 11 .

Note that the embossed film 1 may have seams or seams derived from the pattern master. This is because such seams or seams have little effect on the embossed film 1 if they are in a very small range. For example, if such seams or joints are lines formed by interspersed recesses or protrusions having a size equal to or smaller than the wavelength of visible light, the effect on the embossed film 1 can be reduced. . Also, when the embossed film 1 is a long film, such seams or seams can also be used for specifying coordinates in the embossed film 1 .

As described above, in the embossed film 1 according to the present embodiment, the difference between the loss rate of the recesses 13 at one end of the film body 10 and the loss rate of the recesses 13 at the other end of the film body 10 is 10 ppm or less. That is, the embossed film 1 according to the present embodiment causes little damage to the convex structure or concave structure when the cylindrical or columnar masters are continuously used for transfer. Therefore, even when the concave portions 13 are formed in the film body 10 having a large area, the cumulative increase in the missing portions 15 in the embossed film 1 can be suppressed.

Therefore, the embossed film 1 according to the present embodiment can improve the uniformity of the concave-convex structure in the large-area film body 10 and reduce the frequency of occurrence of the defective portions 15 .

Moreover, it is also possible to cut the embossed film 1 according to the present embodiment described above into a predetermined length to produce a sheet-fed film. Since these sheet films are produced from the embossed film 1 having a highly uniform uneven structure over the entire film, the uniformity of the uneven structure within the sheet film and between the sheet films can be improved.

Furthermore, the embossed film 1 according to the present embodiment described above and a multi-layered sheet film prepared by cutting the embossed film 1 are also included in the scope of the present invention.

[1.2. Example of use of embossed film]
Next, a usage example of the embossed film 1 according to this embodiment will be described with reference to FIGS. 4 to 5B. FIG. 4 is an explanatory diagram for explaining one usage example of the embossed film 1 according to this embodiment.

The embossed film 1 according to this embodiment can be used as a transfer film for arranging fine solids such as fillers on a resin sheet or the like in a predetermined arrangement pattern.

Specifically, as shown in FIG. 4, the recesses 13 of the embossed film 1 are filled with a filler 20 . Next, by pressing the surface of the embossed film 1 filled with the filler 20 against the transfer sheet 30, the filler 20 can be transferred to the transfer sheet 30 side.

By transferring the fillers 20 using the embossed film 1 in this manner, the fine fillers can be easily arranged on the surface of the transfer sheet 30 according to the arrangement pattern of the concave portions 13 formed in the embossed film 1 .

As a method of filling the filler 20 into the concave portions 13 of the embossed film 1, for example, a method of scattering the filler 20 on the embossed film 1 and then wiping the surface of the embossed film 1 with a fibrous body (for example, cloth). etc. can be used. Here, it is preferable that the size of the weave or mesh of the fibrous body used for the wipe is finer than the diameter of the filler 20 .

The filler 20 to be filled in the concave portions 13 of the embossed film 1 may be an inorganic substance, an organic substance, a multi-layered inorganic substance, or a mixture of an inorganic substance and an organic substance (for example, a fine solid made of an organic substance coated with an inorganic substance). ) and the like can be used. Specifically, the filler 20 may be a pigment, dye, or the like. Further, the specific gravity (based on water) of the filler 20 may be, for example, 0.8 or more and 23 or less. Also, the filler 20 may be imparted with various physical properties or functionality.

Although the shape of the filler 20 may be any shape, it is preferably a substantially isotropic shape or a shape obtained by crushing a crystalline substance. The size of the filler 20 may be any size as long as it can be filled into the concave portions 13 of the embossed film 1 . However, the maximum length of the line segment connecting any two points on the contour line of the filler 20 is preferably equal to or less than the minimum length of the line segment connecting any two points on the contour line of the opening surface of the recess 13 .

Here, the recesses 13 of the embossed film 1 may not be filled with the same filler 20 . Specifically, a plurality of types of fillers 20 having different shapes or materials may be filled in the concave portions 13 of the embossed film 1 . By using such an embossed film 1, multiple types of fillers 20 can be arranged on the surface of the transfer sheet 30 at the same time.

In addition, as described above, a coating layer made of an inorganic compound or the like may be formed on part of the surfaces of the convex portions 11 and the concave portions 13 of the embossed film 1 . When a coating layer is formed on part of the surfaces of the projections 11 and the recesses 13, the releasability between the recesses 13 of the embossed film 1 and the filler 20 can be improved. Transferability can be improved.

5A and 5B show a transfer sheet 30, which is a transfer product produced in this way. FIG. 5A is a cross-sectional view schematically showing a cross-sectional shape when a transfer product using the embossed film 1 according to the present embodiment is cut in the thickness direction, and FIG. 5B is the embossed film 1 according to the present embodiment. is a top view showing a planar state of a transfer product using .

Although the material of the transfer sheet 30 is not particularly limited, it is preferably an adhesive sheet, for example. When the transfer sheet 30 has adhesiveness, the transferability of the filler 20 filled in the embossed film 1 can be improved.

When the filler 20 is transferred to the transfer sheet 30 using the embossed film 1 according to the present embodiment, the transfer rate of the filler 20 to the transfer sheet 30 can be 99.99% or more (that is, the defect rate is 100 ppm or less). can. Here, the transfer rate is the number of the fillers 20 transferred to the surface of the transfer sheet 30, which is the number of the concave portions 13 formed in the embossed film 1 (including the missing portions 15 in which the concave portions 13 are not actually formed). Indicates the divided percentage.

One usage example of the embossed film 1 according to the present embodiment has been described above. In addition, the usage example of the embossed film 1 according to the present embodiment is not limited to the above example. For example, the embossed film 1 according to the present embodiment can also be used as a heat insulating or heat radiating material, a matte film, an anti-sticking film, etc., which are known examples of the use of embossed films. It is also possible to use the embossed film 1 according to this embodiment for printed electronics.

In addition, the filler 20 transferred using the embossed film 1 according to the present embodiment can be used for surface decoration (such as polishing) of vehicles, for example. The filler 20 transferred using the embossed film 1 according to the present embodiment, and the application of the transferred body containing the transferred filler 20 are not particularly limited, but for example, the field of printed electronics and its application field ( including related fields), etc. In addition, the transferred filler 20 and the object to be transferred containing the transferred filler 20 can be used as a functional film (or a functional device) without being limited to the above fields. For example, the transferred filler 20 and the transferred body including the transferred filler 20 may be used as biosensors or diagnostic devices in the medical, bio, healthcare, and life science fields, and may be used as optical elements. may be used as In addition, the transferred filler 20 and the transferred body including the transferred filler 20 may be used in the battery or energy-related field, or the vehicle-related field (that is, the automobile-related field).

Alternatively, the embossed film 1 according to the present embodiment may be used to transfer the filler 20 to another film, and the other film to which the filler 20 has been transferred may be further laminated on another film. In this way, by repeating transfer and lamination, a film in which a part or the whole of the filler 20 is provided at a predetermined position of another film is also included in the scope of the present invention.

[1.3. Method for producing embossed film]
Next, a method for producing the embossed film 1 according to this embodiment will be described with reference to FIGS. 6 and 7. FIG. For example, the embossed film 1 according to the present embodiment is obtained by applying a transfer layer 62 (corresponding to the film main body 10) made of a photocurable resin onto a substrate 61 that is a support, and pressing the master 4 against the transfer layer 62. , can be produced by forming recesses 13 in the transfer layer 62 .

The master 4 to be transferred to the embossed film 1 according to the present embodiment can be formed with a concavo-convex structure 41 having an arbitrary arrangement pattern by using, for example, an exposure device 7 shown in FIG.

Specifically, the master 4 having the resist layer formed on the outer peripheral surface thereof is irradiated with laser light from the exposure device 7 to expose the resist layer at positions corresponding to an arbitrary array pattern. Next, after the exposed resist layer is developed, etching or the like is performed on the master 4 on which a resist pattern corresponding to an arbitrary arrangement pattern is formed, thereby forming a concavo-convex structure 41 having an arbitrary arrangement pattern on the master 4 . can be formed.

The configuration of an exposure apparatus capable of drawing any pattern on the master 4 will be described below. FIG. 6 is an explanatory diagram showing the configuration of the exposure device 7 that draws an arbitrary pattern on the master 4 used in this embodiment.

As shown in FIG. 6, the exposure device 7 includes a laser light source 71, a first mirror 73, a photodiode (PD) 74, a condenser lens 76, and an electro-optic deflector (EOD). ) 79 , a collimator lens 78 , a control mechanism 87 , a second mirror 81 , a movable optical table 82 , a spindle motor 85 and a turntable 86 . Also, the master 4 is placed on a turntable 86 so that it can be rotated.

The laser light source 71 is, for example, a semiconductor laser. Specifically, the laser light source 71 may be a blue semiconductor laser that emits laser light with a blue light wavelength of 400 nm to 500 nm. Also, the spot diameter (diameter) of the laser light 70 emitted by the laser light source 71 may be, for example, approximately 200 nm.

A laser beam 70 emitted from a laser light source 71 travels straight as a parallel beam and is reflected by a first mirror 73 . Also, the laser beam 70 reflected by the first mirror 73 is condensed by the electro-optical deflection element 79 by the condensing lens 76 and then collimated again by the collimator lens 78 . The collimated laser beam 70 is reflected by the second mirror 81 and guided horizontally and in parallel onto the moving optical table 82 .

The first mirror 73 is composed of a polarizing beam splitter and has a function of reflecting one of the polarized components and transmitting the other of the polarized components. The polarized component transmitted through the first mirror 73 is received by the photodiode 74 and photoelectrically converted. A light reception signal photoelectrically converted by the photodiode 74 is input to the laser light source 71, and the laser light source 71 modulates the laser light 70 based on the input light reception signal.

The electro-optic deflection element 79 is an element capable of controlling the irradiation position of the laser beam 70 . The exposure device 7 can also change the irradiation position of the laser beam 70 guided onto the moving optical table 82 by the electro-optic deflection element 79 .

The control mechanism 87 also includes a formatter 89 and a driver 88 and controls irradiation of the laser beam 70 .

The formatter 89 generates a control signal for irradiating the master disc 4 with the laser beam 70 based on an input image in which an arbitrary pattern to be drawn on the master disc 4 is drawn. Specifically, first, the formatter 89 acquires an input image in which an arbitrary pattern to be drawn on the master 4 is drawn. The input image is an image corresponding to a developed view of the outer peripheral surface of the master 4, which is obtained by cutting the outer peripheral surface of the master 4 in the axial direction and extending it in one plane. Next, the formatter 89 divides the input image into small regions of a predetermined size (for example, into grids) and determines whether or not each of the small regions contains a drawing pattern. Subsequently, the formatter 89 generates a control signal for controlling the irradiation of the laser light 70 to each small area determined to include the drawing pattern. Furthermore, the driver 88 controls the output of the laser light source 71 based on the control signal generated by the formatter 89 . Thereby, the irradiation of the laser beam 70 to the master 4 is controlled.

A moving optical table 82 includes a beam expander (BEX) 83 and an objective lens 84 . The laser beam 70 guided to the moving optical table 82 is shaped into a desired beam shape by the beam expander 83 and then irradiated onto the outer peripheral surface of the master 4 via the objective lens 84 .

With these configurations, the master 4 is rotated at a constant speed by the turntable 86, and the laser beam 70 is irradiated while scanning the master 4 in the axial direction at a constant speed, thereby performing drawing on the master 4. FIG. The scanning of the laser beam 70 is performed by moving the laser beam 70 in the arrow S direction at a constant speed by the moving optical table 82 .

Also, the master 4 can be formed with the concave-convex structure 41 having an arbitrary array pattern by using another method. For example, the master disk 4 can be formed with the concavo-convex structure 41 having an arbitrary arrangement pattern on the outer peripheral surface by using ultra-precision cutting with a single-crystal diamond tool.

Next, a method for forming the embossed film 1 by pressing the master 4 produced by the above method or the like against the film body 10 will be described. FIG. 7 is an explanatory diagram showing the configuration of a transfer device for producing the embossed film 1 according to this embodiment.

As shown in FIG. 7, the transfer device 6 includes a master 4, a substrate supply roll 51, a take-up roll 52, guide rolls 53 and 54, a nip roll 55, a peel roll 56, a coating device 57, and a light source 58 .

The master 4 is a cylindrical or columnar master on which a concavo-convex structure 41 having an arbitrary arrangement pattern is formed on the outer peripheral surface. The material of the master 4 is not particularly limited, and quartz glass (SiO ₂ ) such as fused quartz glass or synthetic quartz glass, or stainless steel can be used. Although the size of the master 4 is not particularly limited, for example, the length in the axial direction may be 100 mm or more, the outer diameter may be 50 mm or more and 300 mm or less, and the thickness may be 2 mm or more and 50 mm. It may be below.

In addition, on the outer peripheral surface of the master 4, a concave-convex structure 41 is formed which is an inverted shape of the convex portions 11 and the concave portions 13 formed on the embossed film 1. As shown in FIG. Here, the concave-convex structure 41 formed on the outer peripheral surface of the master 4 may have any shape. Note that the outer peripheral surface of the master 4 may be formed with a seam or seam at the time of fabrication. Such seams or seams have little effect on the embossed film 1 if they are in a very small range, and can be used as marks for specifying coordinates on the embossed film 1 .

The substrate supply roll 51 is a roll in which a substrate 61 that is a sheet-shaped support is wound in a roll shape, and the take-up roll 52 winds the embossed film 1 having the uneven structure 41 transferred to the transfer layer 62 . It is a roll to take. Further, the guide rolls 53 and 54 are rolls for transporting the base material 61 . The nip roll 55 is a roll that presses the base material 61 on which the transfer layer 62 is laminated against the master 4 , and the peel roll 56 transfers the uneven structure 41 after the uneven structure 41 is transferred to the transfer layer 62 . It is a roll for peeling off the embossed film 1 (that is, the base material 61 on which the transfer layer 62 is laminated) from the master 4 .

The coating device 57 includes coating means such as a coater, and coats the base material 61 with the photocurable resin composition to form the transfer layer 62 . The coating device 57 may be, for example, a gravure coater, a wire bar coater, or a die coater. Further, the light source 58 is a light source that emits light having a wavelength capable of curing the photocurable resin composition, and may be, for example, an ultraviolet lamp.

In addition, when the light source 58 is a directional light source, the irradiation angle of the light may be inclined from the vertical direction of the transfer layer 62 . In such a case, the transfer rate of the embossed film 1 can be improved because there is a difference in the curing rate on the surface of the uneven structure formed on the transfer layer 62 and the curing is partially performed.

Note that the photocurable resin composition is a resin that is hardened by being irradiated with light of a predetermined wavelength and having reduced fluidity. Specifically, the photocurable resin composition may be an ultraviolet curable resin such as an acrylic resin. Moreover, the photocurable resin composition may contain an initiator, a filler, a functional additive, a solvent, an inorganic material, a pigment, an antistatic agent, a sensitizing dye, or the like, if necessary.

In the transfer device 6 , first, the base material 61 is continuously delivered from the base material supply roll 51 through the guide rolls 53 . A photo-curing resin composition is applied to the delivered base material 61 by the coating device 57 , and the transfer layer 62 is laminated on the base material 61 . Also, the base material 61 laminated with the transfer layer 62 is brought into close contact with the master 4 by the nip rolls 55 . Thereby, the concavo-convex structure 41 formed on the outer peripheral surface of the master 4 is transferred to the transfer layer 62 . After the uneven structure 41 is transferred, the transfer layer 62 is cured by irradiation with light from the light source 58 . Subsequently, the base material 61 (that is, the embossed film 1 ) laminated with the cured transfer layer 62 is separated from the master 4 by the peel roll 56 and wound up by the winding roll 52 via the guide roll 54 .

With such a transfer device 6, the embossed film 1 according to this embodiment can be continuously produced. In the transfer device 6 described above, the base material 61 may be switched to another lot in order to perform transfer continuously.

Images of an example of the embossed film 1 produced in this way are shown in FIGS. 8 and 9. FIG. 8 and 9 are observation images of the embossed film 1 according to this embodiment by a scanning electron microscope (SEM). 8A and 9A are SEM images of the top surface of the embossed film 1, and FIGS. 8B and 9B are cross-sections of the embossed film 1 shown in 8A and 9A taken along line X-XX. It is an SEM image obtained by 8A and 9A, the vertical direction of the SEM image corresponds to the length direction of the embossed film 1, and the horizontal direction corresponds to the width direction of the embossed film 1. As shown in FIG.

Referring to FIGS. 8A and 9A, it can be seen that the embossed film 1 according to the present embodiment can form a concave-convex structure having an arbitrary arrangement pattern. Also, referring to FIGS. 8B and 9B, it can be seen that the depth of the formed concave-convex structure is about 3.4 μm to 3.5 μm.

<2. Example>
Below, the embossed film according to the present embodiment will be described in more detail with reference to examples and comparative examples. The examples shown below are examples of conditions for demonstrating the feasibility and effects of the embossed film according to the present embodiment, and the present invention is not limited to the following examples.

(Example)
An embossed film according to an example was produced by the following steps.

First, a cylindrical master was produced. Specifically, DLC (Diamond Like Carbon) was applied to a film thickness of 800 nm by CVD (Chemical Vapor Deposition) using a hydrocarbon-based gas on the outer peripheral surface of a substrate made of cylindrical quartz glass having a thickness of 4.5 mm. A film was formed to form an intermediate layer. Next, a film of tungsten oxide having a thickness of 55 nm was formed on the intermediate layer by a sputtering method to form a resist layer.

Subsequently, thermal lithography with laser light was performed using the exposure apparatus shown in FIG. 6 to form a latent image on the resist layer. A blue semiconductor laser emitting laser light with a wavelength of 405 nm was used as the laser light source of the exposure device. The exposure pattern used was an array pattern in which circles with a diameter of 7 μm were arranged in a hexagonal lattice at a pitch of 10 μm (distance between the centers of the circles). In addition, the portion other than the 7 μm diameter circle is exposed with an exposure device so that the 7 μm diameter circle becomes a convex portion on the master plate (that is, the 7 μm diameter circle becomes a concave portion on the embossed film after transfer). bottom.

Subsequently, the substrate on which the resist layer was exposed was developed using a 2.38 mass % aqueous solution of TMAH (tetramethylammonium hydroxide) to dissolve the exposed portion of the resist.

Further, using the developed resist layer as a mask, the intermediate layer was etched by reactive ion etching with O ₂ gas. Subsequently, using the resist layer and the intermediate layer as a mask, the substrate was etched by reactive ion etching with a CF-based gas. The substrate was etched until the height of the protrusions reached 7 μm so that the aspect ratio of the recesses in the embossed film was 1. Through the above steps, a cylindrical master plate having a concavo-convex structure formed on the outer peripheral surface was produced.

Subsequently, a base film (thickness 50 μm) made of PET with a width of 50 cm, 100 parts by mass of acrylate resin M208 (manufactured by Toagosei), and a photopolymerization initiator IRGCUR184 (manufactured by BASF) Photocuring resin composition containing 2 parts by weight The material was coated with a film thickness of 30 μm. Further, using the transfer device shown in FIG. 7, the master was pressed against the substrate film, and light was irradiated at 1000 mJ with a high-pressure mercury lamp to transfer the uneven structure to the substrate film for 1000 m. As a result, an embossed film was produced in which circular depressions with a diameter of 7 μm and a depth of 7 μm (aspect ratio of 1) were arranged in a hexagonal lattice with a center-to-center distance of 10 μm. Further, when 100 points in the range of 1 mm ² were observed and measured with an optical microscope, the number density of the concave portions of the embossed film was 11,500/mm ² .

Subsequently, the embossed film according to the example produced as described above was evaluated for the defect rate of the concave portions. Specifically, at each predetermined distance from the transfer start position, a plane field of view of 200 μm×200 μm is observed at a plurality of locations with an optical microscope up to 25 cm ² minutes, and the defects 15 for all the recesses 13 in the observation area are observed. A percentage was calculated. Evaluation of such a defect rate was performed in a transfer distance range of 1 m to 1000 m when the transfer start position from the master was set to 0. Table 1 below shows the calculated defect rate.

As can be seen from the results shown in Table 1, the embossed films according to the examples have a defect rate of recesses at one end of the film (position at a distance of 1 m from the transfer start position) and the other end of the film (transfer It was found that the difference from the loss rate of the recesses at a position 1000 m from the starting position was 1 ppm or less. Therefore, when the length of the embossed film is 1000 m, in the embossed film according to the example, from the position of 0.1% of the total length of the film (that is, the position of 1 m from the transfer start position), 0.1%, 25%, 50%, 75%, and 100% calculated for each 25% to the 100% position (i.e., the position at a distance of 1000 m from the transfer start position) with respect to the entire length of the film It can be seen that the deficit rate at each point is almost the same.

Although not shown in Table 1, the distances of 100 m and 200 m from the transfer start position were the same as the distance of 1 m from the transfer start position. Although not shown in Table 1, the distance of 300 m from the transfer start position was the same as the distance of 250 m from the transfer start position. Furthermore, even between 500m and 750m, the figures were within the range of the loss rate at 500m and 750m. The same was true between 750m and 1000m.

Furthermore, the embossed film according to the example was filled with a resin filler, and the resin filler was transferred to the transfer sheet. As the resin filler, Eposter MA1006 (manufactured by Nippon Shokubai Co., Ltd.), which is a polymethyl methacrylate-based crosslinked product, is used, and the average particle size (diameter) is classified to 5 μm with an image-type particle size analyzer FPIA3000 (manufactured by Malvern). then used.

Embossed films at distances of 1 m, 30 m, and 150 m from the transfer start position are removed, and the resin filler is filled with a fibrous wipe, phenoxy resin YP-50 (manufactured by Nippon Steel Chemical Co., Ltd.) 60 parts by mass, epoxy The resin filler was transferred to an adhesive transfer sheet made of 40 parts by mass of resin JER828 (manufactured by Mitsubishi Chemical Corporation) (the temperature during transfer was 60° C. and the pressure was 2 MPa).

In the same manner as described above, transfer defects of the transferred resin filler (that is, portions where the resin filler is not transferred) were confirmed using an optical microscope. As a result, it was confirmed that transfer defects were less than 1% with respect to all resin fillers in each of the transfer sheets transferred using the embossed films at distances of 1 m, 30 m, and 150 m from the transfer start position. rice field. In addition, no misalignment occurred even in the resin filler that was successfully transferred. The misalignment means that the center position of the resin filler is displaced from the target position by 10% or more of the average particle diameter of the resin filler (0.5 μm in this example). Furthermore, in the transferred resin filler, there was no location where 10 or more transfer failures occurred consecutively in the same direction.

Moreover, in the embossed film according to the example, the concave portions are arranged in a hexagonal lattice pattern, which is the densest arrangement pattern. Therefore, when the embossed film according to the example is filled with the resin filler and transferred, the resin filler is transferred in the densest arrangement pattern. Referring to the results of the embossed films according to the examples, even when the transfer is performed with the densest array pattern, the success rate of transfer of the resin filler is high, the transfer failure is less than 1%, and the position of the resin filler No deviation or the like occurred.

Therefore, when 150 m is 100%, the embossed film according to the present embodiment is 0.67% (i.e., distance 1 m), 20% (i.e., distance 30 m), and 100% (i.e., distance 150 m). It can be seen that stable transfer is possible at . Also, substantially similar results were obtained at each point between 0.67% and 20% and between 20% and 100%. Therefore, the embossed film according to the present embodiment and the transfer material using the embossed film are expected to have the same effect as the example even if the recesses are arranged in any arrangement pattern as long as the recesses are provided. can.

(Comparative example)
Subsequently, an embossed film according to a comparative example was produced by the following steps.

First, by machining a stainless steel flat plate of 10 cm × 10 cm, the same concave-convex structure as in the example (circular protrusions with a diameter of 7 µm were arranged in a hexagonal lattice with a center-to-center distance of 10 µm between the protrusions). A stamper master disk was prepared on which an arrangement pattern and a height of the protrusions of 7 μm) were formed.

Subsequently, a base film (thickness 50 μm) made of PET with a width of 50 cm, 100 parts by mass of acrylate resin M208 (manufactured by Toagosei), and a photopolymerization initiator IRGCUR184 (manufactured by BASF) Photocuring resin composition containing 2 parts by weight The material was coated with a film thickness of 30 μm. By repeatedly pressing the above stamper master against the base film at a temperature of 60° C. and a pressure of 2 MPa, the uneven structure was transferred to produce an embossed film. The stamper master was used by spraying a fluorine-based release agent Daifree GA70500 (manufactured by Daikin Industries, Ltd.) on the transfer surface.

In the embossed film according to the comparative example, every time the transfer was repeated, defects occurred due to resin clogging in the stamper master disc. Specifically, at a point of 20 m (200 times of transfer), the loss rate was evaluated with an optical microscope in the same manner as in the example, and it was 500 ppm (0.5%). In addition, in the embossed film according to the comparative example, since the feeding of the film was not constant, positional deviation occurred in the arrangement of the concavo-convex structure each time the stamper master disc was transferred.

In addition, the embossed film according to the comparative example has a larger misalignment and defect rate of the concave portions than the embossed film according to the example. Therefore, in the embossed film according to the comparative example, it is expected that transfer defects are more likely than in the embossed film according to the example in the same way in the transferred material obtained by transferring the resin filler after filling the resin filler.

From the above results, in the embossed film according to the present embodiment, the difference between the loss rate of the recesses at one end of the embossed film and the loss rate of the recesses at the other end of the embossed film is 10 ppm or less. have understood. Therefore, the embossed film according to the present embodiment can suppress the cumulative increase in defects in the recesses even when the recesses are formed in a film having a large area.

Therefore, the embossed film according to the present embodiment can improve the uniformity of the concave-convex structure in a large-area film and reduce the frequency of occurrence of defects in concave portions.

Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive of various modifications or modifications within the scope of the technical idea described in the claims. It is understood that these also naturally belong to the technical scope of the present invention.

REFERENCE SIGNS LIST 1 embossed film 4 master 6 transfer device 7 exposure device 10 film body 11 convex portion 13 concave portion 15 missing portion 20 filler 30 transfer sheet

Claims (14)

A step of forming a plurality of projections on the peripheral surface of a cylindrical or columnar master and lines formed by interspersing the projections or recesses having a size equal to or smaller than the wavelength of visible light;
A long transferred film having a width of 0.05 cm or more and 300 cm or less and a length of 5 m or more is obtained by applying a photocurable resin composition on a substrate to form a photocurable resin composition layer. and
The photocurable resin composition layer of the obtained transfer film is pressed against the photocurable resin composition layer of the transfer film by rotating and pressing the master, and forming recesses corresponding to the peripheral shape of the master into the photocurable resin composition layer of the transfer film. transferring to and photocuring to create a film body;
The master is formed by etching a diamond-like carbon film formed on quartz glass by a chemical vapor deposition method,
The line formed by interspersed recesses or protrusions having a size equal to or smaller than the wavelength of visible light is a seam or seam,
The diameter of the opening surface of the recess is larger than the wavelength of visible light,
The arrangement pattern of the recesses has periodicity along the length direction of the film body,
When the loss rate of the recesses is calculated based on the recesses in the region corresponding to the same arrangement pattern in one cycle of the arrangement pattern of the recesses, the loss rate of the recesses at one end of the film body and the film body The difference from the defect rate of the recess at the other end of is 10 ppm or less, and the defect rate gradually increases from the one end toward the other end,
The method for producing an embossed film, wherein the number of consecutive missing portions of the concave portion is 10 or less in an area of 10 cm ² of the film main body. 2. The manufacturing method according to claim 1, wherein said recesses formed in said film body have substantially the same shape. 3. The manufacturing method according to claim 1, wherein the arrangement pattern of said recesses is a grid shape. The manufacturing method according to any one of claims 1 to 3, wherein the number density of the concave portions is 50000000/ ^cm2 or less. The manufacturing method according to any one of claims 1 to 4, wherein the film body has a coating layer made of an inorganic compound on at least part of the surface including the inside of the recess. The loss rate of the recesses at each point of 0.1%, 25%, 50%, 75%, and 100% with respect to the entire length of the embossed film is the loss rate of the recesses at one end and the loss rate at the other end. 6. The manufacturing method according to any one of claims 1 to 5, wherein the range includes both ends and the defect rate of the concave portions at the ends. 7. The manufacturing method according to any one of claims 1 to 6, wherein a difference between the defect rate of the recesses at the one end and the defect rate of the recesses at the other end is 1 ppm or less. The production method according to any one of claims 1 to 7, wherein the defect rate of the concave portions is not 0% in the entire film body. The manufacturing method according to any one of claims 1 to 8, wherein the concave portions having the same opening shape have the same depth. A long film body with a length of 5 m or more ,
An embossed film comprising a plurality of recesses formed on the surface of the film body and lines formed by interspersing recesses or protrusions having a size equal to or smaller than the wavelength of visible light,
The line formed by scattered recesses or protrusions having a size equal to or smaller than the wavelength of visible light is a seam or seam derived from the master,
The diameter of the opening surface of the concave portion formed on the surface of the film body is larger than the wavelength of visible light,
The arrangement pattern of the recesses has periodicity along the length direction of the film body,
The difference between the loss rate of recesses at one end of the film body and the loss rate of recesses at the other end of the film body is 10 ppm or less,
The embossed film, wherein the number of consecutive missing portions of the concave portion is 10 or less in an area of 10 cm ² of the film main body. The embossed film according to claim 10, wherein the film body comprises a resin layer. The embossed film according to claim 10, wherein the film body is composed of a curable or plastic resin. The embossed film according to claim 10, wherein the embossed film is a laminate in which a plurality of resin layers are laminated. The embossed film of Claim 10, wherein the recess extends through the film body.

Images